SPP1 and glaucoma: Moreover, the concentrations of secreted protein acidic and rich in cysteine (SPARC), tenascin-C (TNC), thrombospondin-2 (TSP-2), and osteopontin (OPN) were determined by multiplexed immunoassays in patients diagnosed with PACG (n = 41) and controls (n = 22), showing significantly elevated matricellular protein levels in glaucoma patients [77].